1 /* $OpenBSD: getifaddrs.c,v 1.7 2002/01/02 23:00:10 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1995, 1999 5 * Berkeley Software Design, Inc. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 * BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp 26 */ 27 /* 28 * NOTE: SIOCGIFCONF case is not LP64 friendly. it also does not perform 29 * try-and-error for region size. 30 */ 31 #include <sys/types.h> 32 #include <sys/ioctl.h> 33 #include <sys/socket.h> 34 #include <net/if.h> 35 #ifdef NET_RT_IFLIST 36 #include <sys/param.h> 37 #include <net/route.h> 38 #include <sys/sysctl.h> 39 #include <net/if_dl.h> 40 #endif 41 42 #include <errno.h> 43 #include <ifaddrs.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 48 #if !defined(AF_LINK) 49 #define SA_LEN(sa) sizeof(struct sockaddr) 50 #endif 51 52 #if !defined(SA_LEN) 53 #define SA_LEN(sa) (sa)->sa_len 54 #endif 55 56 #define SALIGN (sizeof(long) - 1) 57 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 58 59 #ifndef ALIGNBYTES 60 /* 61 * On systems with a routing socket, ALIGNBYTES should match the value 62 * that the kernel uses when building the messages. 63 */ 64 #define ALIGNBYTES XXX 65 #endif 66 #ifndef ALIGN 67 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 68 #endif 69 70 #if _BSDI_VERSION >= 199701 71 #define HAVE_IFM_DATA 72 #endif 73 74 #if _BSDI_VERSION >= 199802 75 /* ifam_data is very specific to recent versions of bsdi */ 76 #define HAVE_IFAM_DATA 77 #endif 78 79 #if defined(__NetBSD__) || defined(__OpenBSD__) || defined(__FreeBSD__) 80 #define HAVE_IFM_DATA 81 #endif 82 83 int 84 getifaddrs(struct ifaddrs **pif) 85 { 86 int icnt = 1; 87 int dcnt = 0; 88 int ncnt = 0; 89 #ifdef NET_RT_IFLIST 90 int mib[6]; 91 size_t needed; 92 char *buf; 93 char *next; 94 struct ifaddrs *cif = 0; 95 char *p, *p0; 96 struct rt_msghdr *rtm; 97 struct if_msghdr *ifm; 98 struct ifa_msghdr *ifam; 99 struct sockaddr_dl *dl; 100 struct sockaddr *sa; 101 u_short index = 0; 102 size_t len, alen; 103 #else /* NET_RT_IFLIST */ 104 char buf[1024]; 105 int sock; 106 struct ifconf ifc; 107 struct ifreq *ifr; 108 struct ifreq *lifr; 109 #endif /* NET_RT_IFLIST */ 110 struct ifaddrs *ifa, *ift; 111 int i; 112 char *data; 113 char *names; 114 115 #ifdef NET_RT_IFLIST 116 mib[0] = CTL_NET; 117 mib[1] = PF_ROUTE; 118 mib[2] = 0; /* protocol */ 119 mib[3] = 0; /* wildcard address family */ 120 mib[4] = NET_RT_IFLIST; 121 mib[5] = 0; /* no flags */ 122 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 123 return (-1); 124 if ((buf = malloc(needed)) == NULL) 125 return (-1); 126 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 127 free(buf); 128 return (-1); 129 } 130 131 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 132 rtm = (struct rt_msghdr *)next; 133 if (rtm->rtm_version != RTM_VERSION) 134 continue; 135 switch (rtm->rtm_type) { 136 case RTM_IFINFO: 137 ifm = (struct if_msghdr *)rtm; 138 if (ifm->ifm_addrs & RTA_IFP) { 139 index = ifm->ifm_index; 140 ++icnt; 141 dl = (struct sockaddr_dl *)(ifm + 1); 142 dcnt += SA_RLEN((struct sockaddr *)dl) + 143 ALIGNBYTES; 144 #ifdef HAVE_IFM_DATA 145 dcnt += sizeof(ifm->ifm_data); 146 #endif /* HAVE_IFM_DATA */ 147 ncnt += dl->sdl_nlen + 1; 148 } else 149 index = 0; 150 break; 151 152 case RTM_NEWADDR: 153 ifam = (struct ifa_msghdr *)rtm; 154 if (index && ifam->ifam_index != index) 155 abort(); /* XXX abort illegal in library */ 156 157 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 158 if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 159 break; 160 p = (char *)(ifam + 1); 161 ++icnt; 162 #ifdef HAVE_IFAM_DATA 163 dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES; 164 #endif /* HAVE_IFAM_DATA */ 165 /* Scan to look for length of address */ 166 alen = 0; 167 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 168 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 169 == 0) 170 continue; 171 sa = (struct sockaddr *)p; 172 len = SA_RLEN(sa); 173 if (i == RTAX_IFA) { 174 alen = len; 175 break; 176 } 177 p += len; 178 } 179 for (p = p0, i = 0; i < RTAX_MAX; i++) { 180 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 181 == 0) 182 continue; 183 sa = (struct sockaddr *)p; 184 len = SA_RLEN(sa); 185 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 186 dcnt += alen; 187 else 188 dcnt += len; 189 p += len; 190 } 191 break; 192 } 193 } 194 #else /* NET_RT_IFLIST */ 195 ifc.ifc_buf = buf; 196 ifc.ifc_len = sizeof(buf); 197 198 if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) 199 return (-1); 200 i = ioctl(sock, SIOCGIFCONF, (char *)&ifc); 201 close(sock); 202 if (i < 0) 203 return (-1); 204 205 ifr = ifc.ifc_req; 206 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 207 208 while (ifr < lifr) { 209 struct sockaddr *sa; 210 211 sa = &ifr->ifr_addr; 212 ++icnt; 213 dcnt += SA_RLEN(sa); 214 ncnt += sizeof(ifr->ifr_name) + 1; 215 216 if (SA_LEN(sa) < sizeof(*sa)) 217 ifr = (struct ifreq *)(((char *)sa) + sizeof(*sa)); 218 else 219 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 220 } 221 #endif /* NET_RT_IFLIST */ 222 223 if (icnt + dcnt + ncnt == 1) { 224 *pif = NULL; 225 free(buf); 226 return (0); 227 } 228 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 229 if (data == NULL) { 230 free(buf); 231 return(-1); 232 } 233 234 ifa = (struct ifaddrs *)data; 235 data += sizeof(struct ifaddrs) * icnt; 236 names = data + dcnt; 237 238 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 239 ift = ifa; 240 241 #ifdef NET_RT_IFLIST 242 index = 0; 243 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 244 rtm = (struct rt_msghdr *)next; 245 if (rtm->rtm_version != RTM_VERSION) 246 continue; 247 switch (rtm->rtm_type) { 248 case RTM_IFINFO: 249 ifm = (struct if_msghdr *)rtm; 250 if (ifm->ifm_addrs & RTA_IFP) { 251 index = ifm->ifm_index; 252 dl = (struct sockaddr_dl *)(ifm + 1); 253 254 cif = ift; 255 ift->ifa_name = names; 256 ift->ifa_flags = (int)ifm->ifm_flags; 257 memcpy(names, dl->sdl_data, dl->sdl_nlen); 258 names[dl->sdl_nlen] = 0; 259 names += dl->sdl_nlen + 1; 260 261 ift->ifa_addr = (struct sockaddr *)data; 262 memcpy(data, dl, SA_LEN((struct sockaddr *)dl)); 263 data += SA_RLEN((struct sockaddr *)dl); 264 265 #ifdef HAVE_IFM_DATA 266 /* ifm_data needs to be aligned */ 267 ift->ifa_data = data = (void *)ALIGN(data); 268 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 269 data += sizeof(ifm->ifm_data); 270 #else /* HAVE_IFM_DATA */ 271 ift->ifa_data = NULL; 272 #endif /* HAVE_IFM_DATA */ 273 274 ift = (ift->ifa_next = ift + 1); 275 } else 276 index = 0; 277 break; 278 279 case RTM_NEWADDR: 280 ifam = (struct ifa_msghdr *)rtm; 281 if (index && ifam->ifam_index != index) 282 abort(); /* XXX abort illegal in library */ 283 284 if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 285 break; 286 ift->ifa_name = cif->ifa_name; 287 ift->ifa_flags = cif->ifa_flags; 288 ift->ifa_data = NULL; 289 p = (char *)(ifam + 1); 290 /* Scan to look for length of address */ 291 alen = 0; 292 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 293 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 294 == 0) 295 continue; 296 sa = (struct sockaddr *)p; 297 len = SA_RLEN(sa); 298 if (i == RTAX_IFA) { 299 alen = len; 300 break; 301 } 302 p += len; 303 } 304 for (p = p0, i = 0; i < RTAX_MAX; i++) { 305 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 306 == 0) 307 continue; 308 sa = (struct sockaddr *)p; 309 len = SA_RLEN(sa); 310 switch (i) { 311 case RTAX_IFA: 312 ift->ifa_addr = (struct sockaddr *)data; 313 memcpy(data, p, len); 314 data += len; 315 break; 316 317 case RTAX_NETMASK: 318 ift->ifa_netmask = 319 (struct sockaddr *)data; 320 if (SA_LEN(sa) == 0) { 321 memset(data, 0, alen); 322 data += alen; 323 break; 324 } 325 memcpy(data, p, len); 326 data += len; 327 break; 328 329 case RTAX_BRD: 330 ift->ifa_broadaddr = 331 (struct sockaddr *)data; 332 memcpy(data, p, len); 333 data += len; 334 break; 335 } 336 p += len; 337 } 338 339 #ifdef HAVE_IFAM_DATA 340 /* ifam_data needs to be aligned */ 341 ift->ifa_data = data = (void *)ALIGN(data); 342 memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data)); 343 data += sizeof(ifam->ifam_data); 344 #endif /* HAVE_IFAM_DATA */ 345 346 ift = (ift->ifa_next = ift + 1); 347 break; 348 } 349 } 350 351 free(buf); 352 #else /* NET_RT_IFLIST */ 353 ifr = ifc.ifc_req; 354 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 355 356 while (ifr < lifr) { 357 struct sockaddr *sa; 358 359 ift->ifa_name = names; 360 strlcpy(names, ifr->ifr_name, sizeof(ifr->ifr_name)); 361 while (*names++) 362 ; 363 364 ift->ifa_addr = (struct sockaddr *)data; 365 sa = &ifr->ifr_addr; 366 memcpy(data, sa, SA_LEN(sa)); 367 data += SA_RLEN(sa); 368 369 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 370 ift = (ift->ifa_next = ift + 1); 371 } 372 #endif /* NET_RT_IFLIST */ 373 if (--ift >= ifa) { 374 ift->ifa_next = NULL; 375 *pif = ifa; 376 } else { 377 *pif = NULL; 378 free(ifa); 379 } 380 return (0); 381 } 382 383 void 384 freeifaddrs(struct ifaddrs *ifp) 385 { 386 free(ifp); 387 } 388